A method for producing a hollow profile-member having a longitudinal flange is described, for example, in DE 10 2005 011 764 A1. In the known method, a profile-member which is U-shaped in cross-section and which has parallel members is produced in a first bending die. This U-shaped profile-member is subsequently shaped in a second bending die by means of an upper bending die to form a tubular member having a closed cross-section. In this instance, a flange which extends in a longitudinal direction is formed in at least one of the members. In the method known from DE 10 2005 011 764 A1, therefore, the U-shaped profile-member must be removed from the first bending die and be introduced into the second bending die in order to be able to be shaped to form an O-shaped profile-member.
Furthermore, methods for producing hollow profile-members having a longitudinal flange are, at which at least one longitudinal flange member portion is constructed during the shaping of the U-shaped profile-member to form an O-shaped profile-member substantially in a shape-retaining manner to form a portion of the longitudinal flange, are known from GB 1914 01384 A, DE 43 28 441 A1 and U.S. Pat. No. 1,344,105.
Hollow profile-members having a longitudinal flange are used in particular in vehicle construction as bodywork elements. The longitudinal flange serves, for example, to connect metal bodywork sheets. Increasingly high demands are made with respect to the dimensional accuracy of hollow profile-members. This applies in particular to the portions of the hollow profile-members with which the hollow profile-members are connected to other components. These demands are not always met by hollow profile-members which have a longitudinal flange and which are produced using the conventional method since, owing to the transport of the U-shaped profile-member from the first die to the second die, there is necessarily a degree of imprecision when not very complex and cost-intensive measures are taken. This applies in particular to curved hollow profile-members.